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OWhat is a fixed CO2?
Fires onboard ships are not rare events. In fact, fire remains the 2nd principal reason for loss of ships at sea. When at sea, the crew are required to become fire fighters in a fire event, yet this is not their primary role onboard. Ships tend to use fixed CO2 fire suppression systems because it is effective, and CO2 is a cheap agent. Therefore, often contents verification of the CO2 systems is treated as a tick-box exercise.
Why is it important to conduct servicing of marine CO2 fixed gaseous fire extinguishing systems?
A ship’s gaseous extinguishing system typically comprises between 200 and 600 cylinders each containing 45KG of CO2 under high 720 psi/ 49 bar pressure.
Because gaseous extinguishing systems are highly pressurised, the risk of leaking and discharging is accepted as part of their use and this is shown in the regulations that demand their contents checking.
IMO SOLAS & FSS Code Chapter 22.214.171.124 - “Means shall be provided for the crew to safely check the quantity of the fire extinguishing medium in the containers.”
Some marine service companies estimate that 20% of a ship’s CO2 bottles have discharged or partially leaked their contents at some point in their lifetime. Occasionally marine “servicing companies” unintentionally leave it disabled.
According to Lloyds List, almost 10% of all total losses at sea in the last decade were caused by a fire on board. Therefore, the verification of contents is key and ultrasonic liquid level measurement is a quick and simple method to do so.
Why is there a lack of proper testing of CO2 system?
Most marine servicing companies only have four hours on a vessel in a port for contents verification for CO2 containers to 600 cylinders. It is known that it takes 15 minutes for a 2 person team to shutdown, dismantle and weigh a single CO2 cylinder, which is equal to 16 cylinders in four hours. Yet despite this, every CO2 cylinder on the vessel receives a “tested and certified sticker” and the marine CO2 system is certified and a certificate is issued.
Why invest in CO2 Fixed Fire Fighting System Maintenance?
- CO2 is stored under high pressure. This means the agent can leak out the cylinder or accidentally discharge. If it leaks there may be insufficient agent to put out a fire event (scientifically speaking this means “below their design concentration”). So it is important to test the cylinders to ascertain the CO2 leak levels.
- Traditionally testing fire suppression systems has been ascertained by manual weighing which requires the system to be switched off, and thus not protecting the ship for the duration of inspection, then each cylinder has to be dismantled from the manifold, requiring two people to carry the cylinder (45KG CO2 fill usually) onto a weigh scale then returned and recoupled etc which can 15 minutes.
- Today you can use portable ultrasonic gas level indicator, Portalevel® MAX, to check the fill level of agent takes one person and just 30 seconds. If weight is still the preferred result, a calculator can be added to the test kit to convert the level to weight in 30 seconds by an intuitive tablet app, the Portasteele® CALCULATOR.
- This is a key part of fire suppression system ITM.
How often do CO2 tanks need to be tested?
Monthly Testing and Inspections are required to be conducted by the Ship between these events under 4.2 (Fixed gas fire-extinguishing systems) of MSC.1/Circ.1318 IMO Guidelines for the Maintenance and Inspection of Fixed Carbon Dioxide Systems
- Verify containers/cylinders fitted with pressure gauges are in the proper range and the inspection free from leakage
- The only way to determine a cylinder is free from leakage is cylinder contents verification
- The proper range usefully determined under ISO 14520-1 : 2015 Gaseous Fire Extinguishing Systems (for clean agents such as FM-200® or NOVEC™ 1230) as 5% loss of agent contents and 10% loss of pressure and under ISO 6183:2009(E) Carbon Dioxide Extinguishing Systems 10% loss of mass
Checking for 5% loss of contents or checking the charge is at 95% - are the same
- A cylinder can only be determined as free from leakage and within the proper range is by checking its contents – either by weighing or by ultrasonic fill level sensor
- For good reason a crew is not qualified or certified to dismantle, weigh and re-install high pressure CO2 systems which by definition in a dynamic not static state
- Disturbing pressurised CO2 systems is dangerous and the reason why only an Accredited Service Agent can shutdown, dismantle, weigh (for contents) and re-install a High Pressure fire extinguisher system and its cylinders
- The only way therefore, that a ship can meet its obligations to conduct that element of the monthly inspection is to check the cylinder contents safely and accurately with an ultrasonic level sensor
How can you tell how much gas is in a cylinder?
Using a marine tank level indicator is the only way that the crew can safely undertake periodic testing of containers without disturbing them. Coltraco Ultrasonics designed the Portalevel® MAX Marine & Portamarine® gas level indicator gauge, as radioactive units were being phased out. Now, Coltraco have a range of liquid level measurement devices.
If shipping companies implemented the IMO SOLAS FSS codes by testing safely and quickly (just 30-60 seconds per cylinder) by using CO2 system checker and marine servicing companies were able to do their work without allowing for time pressures, then vessels would be far safer.
How can I test multi-banked cylinders?
Marine CO2 Fire Suppression systems are almost always stored in two, three or four rows deep. As such, marine level testers comes with a dedicated extension arm, allowing the operators to reach through and easily test the rear rows of cylinders.
How do you use a CO2 indicator?
The Portalevel® gas level indicator is an easy tool for testing CO2 systems and contents inspection.
- Place level sensor at the top of the container, on the flat surface below the neck and the top dome.
- Move ultrasonic sensor down the container in small steps & observe readings. In the region with higher readings press CAL (full bar graph).
- Observing the bar graph, move sensor in small steps to the region with low readings. The bar graph will disappear when you pass the liquid level
- Move sensor back in small steps until the bar graph reappears. The exact point between the bar graph disappearing and reappearing is your liquid level
How do I calculate the liquid level in my tank?
The Portalevel® MAX Marine electronic gas level indicator allows the crew to be in charge of checking the high press CO2 systems, as many times as needed: ensuring that the systems will be working when they are needed.
- ABS Type Approved Portalevel® MAX Marine level ultrasonic sensor is designed primarily for the vessels’ crew to inspect large fire suppression agent systems of up to 600 cylinders.
- The ease of operation in comparison to weighing, increases the ability of more regular and frequent checks, improving fire safety management onboard.
- Coltraco’s high quality innovative method of inspecting leaking cylinders with ultrasonic level measurement, enables identification in under 30 seconds using Portalevel® with one person, instead of the traditional 15 minutes, with two people laboriously weighing.
Combined with the MAX Marine surveying equipment, the Portasteele® CALCULATOR is an advanced application, that converts the liquid level height of C02, NOVEC™ 1230 and FM-200® liquefied gaseous extinguishant agent readings taken on a Portalevel® device into the agent weight/mass. The Portasteele® CALCULATOR can convert an expected agent weight back to the required liquid level allowing users to anticipate where the level should be as part of a fire system inspection. Portasteele® CALCULATOR converts the liquid level tank readings into a weight measurement, logging the recorded data with easy exporting via email. By reducing time needed for reports, more time can be spent on ensuring the safety of the vessel.